A health advisory for Claybank Creek has been issued following a sewage spill at Fort Rucker.
The leak was apparently caused by a pump malfunction.
Authorities have warned against swimming or eating fish from the creek until environmental officials complete an assessment of the damage.
The plant treats about 60,000 gallons per hour but it was not known how long the pump was out of service.
Claybank Creek begins at Lake Tholocco and flows south into the Choctahatchee River.
Health and environmental agencies from the state and Dale County are assisting Fort Rucker with the accident investigation.